If you’re getting some type of pocket pistol, you generally have a choice between .32 ACP and .380 ACP. But there are plenty of other options too – there are still pistols available with smaller calibers – the .25 Auto and even various types of .22 LR cartridges are sometimes featured in sub-compact pistols.

And you can get 9mm pistols that are only a little bigger than some of the .380 Auto chambered pistols. Then you might think to yourself that if you’ve gone a little bigger, up to a 9mm caliber pistol, it is only another relatively small step to .40 S&W, and so on and so on beyond that.

Where to start and where to stop?

How Underpowered is Too Underpowered? How Powerful is Too Powerful?

If you have to set cut-offs for too big and too small, then let’s arbitrarily set them as anything less than .32 ACP is too small and anything bigger than .380 ACP is too big.

But this is just for the sake of simplicity. Any gun of any caliber is better than no gun at all, and bigger is usually better than smaller (assuming the gun remains controllable without too much recoil).

Here’s a heart warming story of a woman who killed an attacker with a single shot from a .22 caliber derringer she had hidden in her bra – and judging by the picture of the attacker, he was a big man. However, being able to incapacitate an attacker with a single .22 round is extremely unusual, and you’d be very well advised not to rely on such an underpowered round for your own future safety.

Your Two Main Choices – .32 ACP and .380 ACP

The .32 ACP tends to have a round weighing 65 – 71 grains, a velocity of 925 – 900 ft/sec and 123 – 128 ft lbf of energy (the velocity and energy figures assume a 4″ barrel – your pocket pistol will have a much shorter barrel, so will develop less velocity and energy).

As you can see from these stats, the larger .380 is almost 50% heavier, 10% faster, and has 60% more energy. It is definitely a superior round.

But why stop there? If you upgrade further to a 9mm chambered pistol, you will have rounds weighing 115 – 147 grains, traveling at 990 – 1430 ft/sec, and with 320 – 520 ft lbf of energy (the upper numbers being +P+ loaded cartridges). That’s twice the weight and three times the power of the .32 ACP, and 30% or more weight compared to the .380 ACP and about twice its power.

And then, of course, there’s .40 S&W and .45 ACP and so on and so on. Where to stop? (Answer = A .50 BMG caliber Barrett rifle, firing a 650 – 800 grain bullet out of a 35″ barrel at about 3,000 ft/sec and with up to 15,000 ft lbf of energy!)

A rifle weighing 30lbs or more and 4 ft long is clearly not concealable. So let’s return to reality, and remember that our prime consideration here is a pistol you will always carry that is ultra-concealable. You are sacrificing some power and magazine capacity in return for smaller size, lighter weight, and greater concealability. The issue is simply how far you should go on this sacrificial scale.

To look at the lower end of the energy scale, a .25 Auto round weighs about 35 – 50 grains, travels at 760 – 900 fps, and generates about 63 – 66 ft lbf (these figures from a 2″ barrel). It is massively slower, lighter, and less powerful than even the .32 ACP.

In case you wonder, a .22 LR is in some respects more powerful than the .25 Auto. Although the bullets are smaller (30 – 40 grain), they are faster (1000 – 1400 fps) and have more energy (100 – 150 ft lbf).

For the truly small pocket pistols, you probably should limit yourself to .380 ACP. Try and skip the .32 ACP because there’s not really any extra advantage in terms of size/weight to justify the reduction in ‘stopping power’ between the .380 and .32 rounds, and don’t get a too small and light pistol in a heavier caliber.

If you really want 9mm or bigger/better (and good for you if you do) then get a ‘proper’ sized pistol to go with it so you’ve a more stable and accurate firing platform to work with.

I have a 9mm (FNX 9), a 40S&W (SD40VE) and a .22lr (Sig Mosquito), all regular size handguns that just wont cut it. I need a truly concealable item that will not hinder me in any way. Carrying any of those three on my side takes a big toll on me and, no matter what holster I use, it still prints because I tend to be very athletic and stretch down too much.

I don’t want my firearms to dictate my every posture, I want one that will suit my posture. For this reason, I’m going with a pocket handgun (either front or wallet type holstered). A small 380 is my choice.

.380 is on average 25% heavier than a .32 your math is off a bit, but obviously, bigger faster and more energy is better. Bullet choice is also important. No sense in using a bigger faster round if its just going to whistle right through and not expand and create a cavernous wound channel